Robot navigation research at CESAR

The core of the navigation program for the Oak Ridge CESAR (Center for Engineering Systems Advanced Research) robots is a production system developed on the expert system shell CLIPS, which runs on an NCUBE hypercube aboard the robot. The production system can call on C-compiled navigation procedures. The production rules can read the sensor data and address the robot's effectors. This architecture was found to be efficient and flexible when used for the development and testing of the navigation algorithms. However, to process unexpected emergencies intelligently, it was necessary to control the production system through externally generated asynchronous data. This led to the design of an asynchronous production system, APS, which is being developed on the robot. Some of the navigation algorithms developed and tested at CESAR are reviewed, and the need for APS, and how it is being integrated into the robot architecture, are discussed. >